Process of bleaching nuts



Oct. 27, 1925.

A w CHRISTIE PROCESS OF BLEACHING NUTS Filed April 3o. 1925 31a/vento@ @ima/b '3l/'Malay Patented oa. 21, 41925.-

luluTliie STATES PATENT oFFlcE.

ARTHUR W. CHRISTIE, OF BERKELEY, CALIFORNIA, ASSIGNOR TO CALIFORNIA WAL- NUT GROWERS ASSOCIATION, OF LOS ANGELES, CALIFORNIA, A CORPORATION F CALIFORNIA.

rnoenss or nLEAcHING. Nurs.

Application led April 30, 1925. Serial No. 26,859.

To all whom #may concern:

Be it known that I, ARTHUR W. CHRIsTm, a citizen of the United States, residing at Berkeley, in the county of Alameda and State of California, have 'invented a new and useful Process of Bleaching. Nuts, of which the following is a specification.

`This invention relates toa 'process of bleaching nuts and is more particularly din rected to an improved process for bleaching walnuts.

Various processes now in use for the bleaching of nuts, particularly walnuts, which processes are, for

the most part,'dependent upon the bleaching action of nascent chlorine. These processes, however, do n ot produce -a satisfactory7 bleach and do not bleach all ofthe nuts so treated uniformly.l

I have discovered that very satisfactory results are obtained by treating nuts, particularly walnuts, 'irst vwith a solution .from

which nascent chlorine is liberated during.

the primary bleaching step, and, secondly, by treating the product from this primary step with a solution of sulphurous acid and that this process, as briefiy stated, produces a uniform, bleached product without regard ato the condition of color and the like of nuts prior to their treatment.. i

`An object ofv this invention is, therefore, to A'provide a process for bleaching nuts which will provide a uniform andA satisfactorily bleached product. i i

vention will be apparent from the following detailed deseriptlon thereof, reference being had to the accompanying diagrammatic drawing.` 1 The preferred embodiment comprises the following ste s, the first step of .which consists of intro ucig a chlorine-containing or *liberating solution into a revolving 'drum through which-the nuts lto. be bleached are conveyed by an suitable means, such as the conve ors whic are diagrammatically illus- 'tratecll lAny solution may betused for the purpose of j nascent chlorine such as is obtained b the 5 treatment of a hypochlorite with an' acld, or v the like; any one of. which will produce a. high .concentrationof active chlorine. Because of ease in reparation and the ease handling thereof the following method. is

have been used Iand are Other objects and advantages ofmy in' providing the requisite active o1 r preferred for the production of the requisite chlorine:

Twenty-five pounds of chloride of lime (calcium hypochlorite) are `dissolved in twenty-five gallons of cold water by first making a thick paste of the chloride of lime with a small portion of cold water inv approximately a fifty gallon container. The container is then filled approximately half full of cold water and the same thoroughly stirred to dissolve the chloride of lime.

t A solution is in the meantime prepared of slx pounds of sodium carbonate mono hydrate-crystals using sufficient water so that the crystals will be thoroughly dissolved by stirring. The two' solutions are then. poured together and the barrel illed with cold water.

The solution is then allowed to stand for approximately twenty-four hours to allow the Vprecipitated calcium carbonate to settle.

An acid solution of approximately eight fluid ounces of commercial* concentrated sulphuric acid is addedto five ygallons of water. The solution of chloride of lime and sodium carbonate mono hydrate crystals is allowed to settle in the tank B. The Solution of acid is contained in the tank C which is preferably lined of porcelain or like material.

In many cases it is preferable to obtain the yrequisite active chlorine from the method which depends on the preparation of a solution of sodium hypochlorite by passing chlorine gas into a solution of sodium hydroxide; which method offorming the desired bleachingy solution to provide nascent "chlorine of high concentration is well understood in the art. v

The valve 2 connected in the line 3 above the entrance ofthe line 4 from the tank C is regulatedv as is the valve 5 in the line 4 so' as to mix the solution from thetank B f commonly termed the lime solution, with the acid solution from` the tank C in the proportions ofvfifteen 4parts of lime solution to onepart of acid solution. The solution is then admitted .in the revolving drum A and Hows through the revolving drum in the direction indicated by the arrows and exhausts through a valved line 6v to a waste solution tank 7. In many instances it may be preferable to merely dip the walnuts into this solution of fifteen parts of lime solution to one part of acid solution.

entrance end of the The nuts leaving the drum A or after having :been dipped into the mixed acid and lime solution, are conveyed asfdiagrammaticall'y illustrated at 8 to. a second revolving drum D which likewise has( veins'9 for conveying- .the nuts from the .entrance end there# through. The nuts leaving the drum D are vdelivered upon a second conveyor l0 and thereafter dried. `The nuts are. preferably 10 dried in slatted bins .1( not shown) thereby permitting. further action of the sulphurous l)acid solution absorbed by and mechanically held by the shells of the nuts.

vThe tank E contains a Asolution of sulmV phurous acid prepared either by the use of Nansp,+n2s04fsa+n+nansa l have discovered that the concentraticn lof this sulphurous acid solution should be for more practical reasons between 6.5% and 6.00% and also that practically the' same results are obtained by the use of an f0.5% solution of sulphurous acid as are obtained with `a 6% soluticn.- The sulf phurous acid is delivered to the drum D through a valved conduit 11. An outlet loverflow pipe or conduit 12 having a valve 13 is provided for regulating the level of 40 the duid within the drum l). The dilute vsulphurous acidsolution is delivered -to a tank 14 orthe Asaine may be disposed of. In somev cases it may be desirable to save the waste sulphurous acid liquor and by the 5 addition of new sulphur dioxide bring this solution back to the required concentration. The speed of revolution of the drum A is 'preferably such that the nuts traveling therethrough require from one to three minutes, depending upon their condition of cleanliness prior to their introduction therein.` t

" While I have diagrammatically illustrated a form of apparatus that may be employed for carrying out my invention, it is to be understood that my invention relates to the process of bleaching nuts which com-- prises irst subjecting the nuts to the action of active chlorine and then subjecting the nuts to the action 'of sulphurous acid and that the same is not dependent upon any particular form. of apparatus which may be varied tov suit any conditions or operation desired, and further, that my invention is of the scope of thegappended claims.

ll claim:

1. A process of bleaching nuts comprising immersing the nuts in a solution from which nascentfchlorine is'being liberated and then immersing the-nuts in a solution Aof sulphurous acid.

2. The process of bleaching nutslconsisting of immersing the nuts in a solution from which nascent chlorine is being liberated and then immersing the nuts into afsolution of between 0.5%` to 6.00% sulphurous acid. l

3. The process 'of bleaching walnuts comprising immersing thel nuts in a solution from which nascent chlorine is being liberated,` conveying the nuts to a second bleaching chamber, immersing the nuts into a soluv, tion of sulphurous acid, and drying the nuts so treated. l f 4. rlihe process of bleaching nuts which aoA consists in subjecting the nuts to action of a solution in.which active chlorine is being liberated for a period of from jl` to 3 minutes, and then subjecting the nuts to the action of sulphur dioxide. Q

5. Aprocess of ,bleaching nuts which consists in subjecting the nuts to action of a solution Vin which active chlorine is being.

liberated, immersing the nuts ina solution containing sulphurous acid, and drying the nutswithout rinsing the sulphurous acid therefrom.. i

Signed 'at Berkeley` California, this 16th `day of April 1925. 'l

'ARTHUR w. cnais'rin, 

